Here's why:
* Historical context: Ghosts were generally seen as bad omens in Elizabethan England. They were associated with death, vengeance, and the disruption of the natural order.
* Horatio's character: Horatio is a scholar and a reasonable man. He is initially skeptical of the ghost's existence but also cautious about its potential significance.
* His initial reaction: Horatio says, "This bodes some strange eruption to our state," He uses the word "eruption," which implies a violent and disruptive event.
Later, as the ghost reveals its identity and purpose, Horatio's understanding shifts. However, his initial reaction underscores the significance of the ghostly apparition as a symbol of impending doom and a harbinger of the play's tragic events.